fix: stop relying on semver as it could be missing in the root node_modules

[DimitarTachev]

PR Checklist

• [x] The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• [ ] There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• [x] You have signed the [CLA].
• [x] All existing tests are passing: https://github.com/NativeScript/nativescript-dev-webpack/blob/master/CONTRIBUTING.md#testing-locally-by-running-e2e-tests
• [ ] Tests for the changes are included.

What is the current behavior?

We are relying on semver while it could be missing in the root node_modules

What is the new behavior?

We are not relying on semver

[vakrilov]

The code file with the hook lives inside the nativescript-dev-webpack package (ehich has semver dependency). So it is ok to rely on it.

It is not ok to rely on semver inside the generated hook file. But in this case it will just execute the script form inside the ns-dev-webpack package.